[danman]

After recently buying a 4B-ST I am now looking into getting a pre-amp. (I have a loaned YBA 2alpha for now which is also great). I want to stick with the Bryston make and have noticed a Bp6 for sale at 1000$ but I have also asked James to look for a used BP20 for me as well because he was the one that found my amp for me and I am eternally greatful!

The BP20 has balanced connections and the BP6 does not. Also the BP20 should be a little cheaper (cost wise!) and I was wondering which one would be the better of the 2 for my use.

Thank you

[Sasha]

My experience so far was that balanced connections sound noticeably better, regardless of manufacturer/device in question (source, pre-amp or amp), assuming it had properly designed balanced I/O circuitry, it was not just a question of noise rejection or cable length but clearly audible difference in overall performance.
So I would go for BP20.

[Stu Pitt]

All things being equal, you can never go wrong buying the best piece you can.  The BP20 is a better pre-amp.  You should however factor in things like the number and types of inputs needed, remote control, amount of warantee left, and so on.  Then comes price.

Balanced connections sound better, if designed properly.  Bryston designs and builds everything properly.

[vegasdave]

The BP6 however, is the same as the BP26 except for the internal power supply, and yes, the lack of balanced inputs/outputs.

I would go for the BP6. It's a newer unit, and it has higher resale value right now

[danman]

I think I would rather go with the BP20 myself. I have used balanced before and have noticed a better quality sound. Anybody know where I can get one used ??????????

Thanks

[robinje]

I was under the impression that Bryston preamps do not have truly balanced circuitry in their gain stages.  This would imply that an incoming balanced signal would need conversion to single ended to run through the gain stage, then back to balanced if using balanced connections to a power amp.  That seems like a lot of extra balanced--single ended--balanced conversions going on (and extra circuitry in the signal path) compared to simply using unbalanced cables all the way from source to amp.  Assuming cable runs are relatively short and there's not a huge source of electro-magnetic noise in the area, it seems that single ended connection would be the way to go.  Am I off my rocker here?  If so, why would balanced sound better? 

[Stu Pitt]

I was under the impression that the pre-amps do have truly balanced circuitry in their gain stages.  Maybe James can shed light on it?

[robinje]

I searched the forum on the balanced vs. unbalanced issue.  Here are a few quotes I observed (please note the underlined portions)...

Quote from: James Tanner on May 14, 2008, 02:43:38 pm
Quote from: Gary Listen on May 13, 2008, 05:03:26 pm
James,

Regarding balanced and unbalanced lines, does Bryston use "phase splitters" in the analog output stage to create the balanced output signals in the BCD-1 and SP-2, or are the balanced signals created in the digital domain?  Also, if a balanced signal is input into the SP-2, does the SP-2 convert the balanced signal to an unbalanced signal for its internal gain stages?

Thanks




Hi Gary,

Answer from Engineering:

Hi James;

Bryston uses input buffers on our amps and preamps, regardless of whether the signal arrives balanced or unbalanced.   The buffers have gain, reducing the gain requirements in following stages, and in fact reducing overall distortion in the amp or preamp.  They also, in the case of the preamps, allow lower-value volume and balance controls, reducing noise.

In electronic balancing the common-mode noise that arrives on the cables is cancelled when the signal is converted to single- ended, so this is a necessary step .

cwr





Hi Gary,

Follow up answer from Engineering.

Hi James;
 
Bryston does use a phase splitter output circuit, in the form of a pair of discrete op-amps driven in opposite polarlty.  This produces an output of twice the Voltage, to reduce the requirement for gain in the following components.  It is done entirely in the analog domain.  Bryston's balanced input stages use differential amplifiers to both convert the signal to single-ended, and to mathematically cancel any noise picked up on the cables.
 
cwr

My question is...  if EMI/RFI and long cable lengths are not a major issue, why bother with balanced connections and the inherent additional electronic complexity involved in the back-and-forth conversions?  Wouldn't a well-shielded single-ended cable between the components be a simpler solution with less need for the signal to be electronically manipulated (i.e. phase splitters, buffers, transformers, etc.)? 

[rob80b]

I would go for the BP6. It's a newer unit, and it has higher resale value right now

Sometimes!
http://www.audiogon.com/cgi-bin/cls.pl?preatran&1228831251&/bryston-Bp6-

[vegasdave]

That's just ridiculous...the BP6 is worth more than that!

Anyway, I feel the best Bryston preamp is the BP16!

[vegasdave]

I think I would rather go with the BP20 myself. I have used balanced before and have noticed a better quality sound. Anybody know where I can get one used ??????????

Thanks

Have you compared it directly to the BP6?

[James Tanner]

I searched the forum on the balanced vs. unbalanced issue.  Here are a few quotes I observed (please note the underlined portions)...

Quote from: James Tanner on May 14, 2008, 02:43:38 pm
Quote from: Gary Listen on May 13, 2008, 05:03:26 pm
James,

Regarding balanced and unbalanced lines, does Bryston use "phase splitters" in the analog output stage to create the balanced output signals in the BCD-1 and SP-2, or are the balanced signals created in the digital domain?  Also, if a balanced signal is input into the SP-2, does the SP-2 convert the balanced signal to an unbalanced signal for its internal gain stages?

Thanks




Hi Gary,

Answer from Engineering:

Hi James;

Bryston uses input buffers on our amps and preamps, regardless of whether the signal arrives balanced or unbalanced.   The buffers have gain, reducing the gain requirements in following stages, and in fact reducing overall distortion in the amp or preamp.  They also, in the case of the preamps, allow lower-value volume and balance controls, reducing noise.

In electronic balancing the common-mode noise that arrives on the cables is cancelled when the signal is converted to single- ended, so this is a necessary step .

cwr





Hi Gary,

Follow up answer from Engineering.

Hi James;
 
Bryston does use a phase splitter output circuit, in the form of a pair of discrete op-amps driven in opposite polarlty.  This produces an output of twice the Voltage, to reduce the requirement for gain in the following components.  It is done entirely in the analog domain.  Bryston's balanced input stages use differential amplifiers to both convert the signal to single-ended, and to mathematically cancel any noise picked up on the cables.
 
cwr

My question is...  if EMI/RFI and long cable lengths are not a major issue, why bother with balanced connections and the inherent additional electronic complexity involved in the back-and-forth conversions?  Wouldn't a well-shielded single-ended cable between the components be a simpler solution with less need for the signal to be electronically manipulated (i.e. phase splitters, buffers, transformers, etc.)? 

Hi Robin,

The answer to your question is YES. There has always been this issue with Balanced vs Unbalanced lines and the plus and minus of both. So if your system uses short interconnects then the advantages of common mode noise cancellation in Balanced circuits are not as critical. In that case the single ended unbalanced input (RCA) makes sense. If your running long interconnects where the amps are a long way from your source components and your using short speaker cables the Balanced XLR interconnect lines make sense.

Also there are a number of ways to do Balanced lines (transformers, IC's, Discrete operational amplifiers etc.) and how well these circuits are implemented affect the overall performance of your system

The issue I see though is that in the real world we are constantly being bombarded by RF and other types of electromagnetic energy (cell phones, florescent light etc.) so using Balanced lines will prevent the outside world from affecting the noise floor of your system. In our case we spend a lot of time developing products that have incredibly low noise floors and to give that all up to ravishes of outside RF influences reduces the performance benefits we work so hard to achieve.

So definitely try both ways (Single ended and Balanced) and see which sounds best in your particular setup.

james

[robinje]

Thanks for your thorough response!